Kara: So, J'onn says to head straight back to the DEO, and if we scratch his car, he'll put us in containment.Alex: Well, you'd better let me drive, then.Kara: Why? I'm a great driver.Alex: You almost killed us twice coming up here.Kara: That possum came from nowhere.

As they are fleeing the alien base, Supergirl and the others run towards the portal, Winn activates it and jumps through. In a following shot (after a 'friendly' alien helps them), he is standing behind Supergirl again.